Storm sewer drainage grate filter

ABSTRACT

A storm sewer drainage grate filter for above grade installation and use includes a frame and a screen supported by the frame. The frame may include a top ring, a bottom ring, and one or more intermediate rings. The rings may be interconnected by a plurality of risers. A method directed to fitting a storm sewer grate filter apparatus to a storm sewer opening includes installing an above grade grate filter having a frame and screen supported by the frame, allowing debris to accumulate on the exterior of the grate filter, and clearing the debris from the exterior of the grate filter.

FIELD

The present invention is related to a stormwater filtration apparatus and method of use, and more particularly, to an above-grade storm sewer filtration apparatus and method of using the same.

BACKGROUND

Surface water runoff is a primary way that sediment and debris residing on the ground surface is introduced into stormwater systems, including storm sewers. Surface water runoff sweeps sediment and materials into the flowing water and sends it into the stormwater systems. To address this problem, sites are increasingly using systems for screening and/or filtering out sediment and other materials prior to allowing the surface water to be discharged into surface waterways, such as rivers and streams. Thus, one way of mitigating sediment and materials from entering the waterways is to use one or more systems or apparatus for screening and/or filtering out sediment and debris prior to allowing the surface water to enter storm sewers.

Many devices found in the prior art are designed to be positioned within the storm sewer, or within a vault associated with the storm sewer. For example, U.S. Patent Application Publication No. 2004/0016692 discloses a filtration bag that is positioned below an inlet grate of the storm sewer. Similarly, U.S. Patent Application Publication No. 2005/0183997 discloses a cylindrically configured filter basket system that is positioned below grade at a street curb. Likewise, U.S. Patent Application Publication No. 2003/0034286 discloses a cylindrically configured filter that resides in a catch basin placed below the ground surface.

In all the above-summarized U.S. Patent Application Publications, the filtering device is positioned below grade. However, depending upon site-specific conditions, such devices can be difficult to access for removal of accumulated sediment and debris. Such below grade filters may require a two-person cleaning and inspection team because a first person performs the work while second person monitors safety conditions, or alternatively, the second person assists with the efforts associated with the cleaning process. Thus, there is a need for a storm sewer filtration apparatus that provides improved maintenance capabilities after sediment and/or debris has been trapped or otherwise prevented from entering the storm sewer. Accordingly, it would be advantageous to provide an above-grade filtering device.

SUMMARY

In accordance with embodiments of the present invention, a storm sewer drainage grate filter is provided for filtering sediment and debris at ground level. In accordance with at least one embodiment of the present invention, the drainage grate filter includes: (1) a base ring sized to fit over the storm sewer inlet; (2) a top ring; (3) at least one intermediate ring; (4) a plurality of risers connecting the top ring, base ring and the at least one intermediate ring; and (5) a passage limiting structure, such as a screen or perforated material wrapped around the exterior of the support structure.

In a preferred embodiment, the support structure of the drainage grate filter comprises a plurality of risers, the ends of which are connected to the upper face of the base ring and the lower face of the top ring. Further, the support structure comprises one or more smaller intermediate rings installed between the top and base rings along the same axis. Further, the exterior radial surface of the intermediate rings is joined to the interior lateral surface of the risers so as to provide supplemental strength against buckling of the risers caused by side or lateral loading resulting from sediment, debris, and/or hydraulic water pressure. Alternatively, the intermediate rings may be of a larger diameter than the top and bottom rings.

In a preferred embodiment, the top ring, base ring, support structure, and screen are all made of steel. Further, the screen is made of expanded metal. Alternatively, the screen can be made of a perforated metal or metal mesh. The screen can also be made of a plastic and/or geosynthetic material, such as a geogrid, geonet, and/or geotextile filtering media either used alone or in conjunction with a metal screen.

An alternative embodiment uses square or rectangular rings instead of circular rings consistent with the shape of the storm sewer opening being square or rectangular rather than circular. Yet another alternative embodiment utilizes riser members for the support structure that are not vertical and/or straight. That is, the risers may be oriented other than perpendicular to the ground, and/or the risers may be non-linear.

In accordance with at least one embodiment of the present invention, an existing storm sewer grate or cover is removed and replaced by a drainage grate filter comprising the present invention, wherein a base ring of the drainage grate filter is positioned in the space formerly occupied by the storm sewer grate or cover. The support structure of the drainage grate filter extends upward from the storm sewer entry. Although possible, it is not necessary to fixedly attach the drainage grate filter to the storm sewer entry because the weight of the drainage grate filter should generally be sufficient to hold the drainage grate filter in place.

Maintenance personnel can access the drainage grate filter for installation, inspection, and cleaning without having to enter or reach inside the storm sewer. More particularly, embodiments of the present invention advantageously provide access to the drainage grate filter at ground level, which allows for relatively easy installation, maintenance, and removal operations associated with the gathering and removal of accumulated sediment and/or debris that is retained by the drainage grate filter. Thus, the present invention is generally more accessible than prior art devices that require positioning below grade level.

Various embodiments of the present invention are set forth in the attached figures and in the detailed description of the invention as provided herein and as embodied by the claims. It should be understood, however, that this Summary does not contain all of the aspects and embodiments of the present invention, is not meant to be limiting or restrictive in any manner, and that the invention as disclosed herein is and will be understood by those of ordinary skill in the art to encompass obvious improvements and modifications thereto.

Additional advantages of the present invention will become readily apparent from the following discussion, particularly when taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a preferred embodiment of the present invention;

FIG. 1B is a perspective view of the device of FIG. 1A with screen top;

FIG. 2 is a perspective view of the top portion of a preferred embodiment;

FIG. 3 is an alternative perspective view of the top portion of a preferred embodiment;

FIG. 4 is a perspective view of a preferred embodiment looking down from the top portion through the middle of the invention at the storm sewer opening;

FIG. 5 is a partial side elevation view of a portion of the frame of a preferred embodiment;

FIG. 6 is a side elevation view of an embodiment of the present invention; and

FIG. 7 is a side elevation view of an embodiment of the present invention.

The drawings are not necessarily drawn to scale.

DETAILED DESCRIPTION

The present invention is directed to an above grade sewer drainage grate filter. The grate filter of the present invention has a number of distinct advantages over prior art grate filters. First, an above grade device is safer because it can be accessed at ground level rather than requiring entry into a confined space such as a sewer. Second, an above grade filtering device is easier to inspect and clean when necessary. Below grade filters require one person and sometimes a two-person team to inspect and clean them via either an access hole or by entering a confined space that may contain noxious gases and/or other hazards. Finally, an above grade filtering device is easier to install than a below grade filtering device, because all that is required to install an above grade filtering device is to set the device in place of the grate/cover.

With reference to FIG. 1A, a storm sewer drainage grate filter constructed according to embodiments of the present invention is generally identified by numeral 10. The drainage grate filter 10 is installed above grade and includes a frame 15 and a passage limiting structure, such as a screen 26 supported by the frame 15. In accordance with at least one embodiment of the present invention, the frame 15 includes a base ring 14, a top ring 32 and, one or more intermediate rings 22. The rings 14, 22, and 32 are interconnected by a plurality of risers 18. The frame 15, including the risers 18 and the rings 14, 22 and 32, forms a support structure for a screen 26. The base ring 14 of drainage grate filter 10 is intended to be installed on top of a storm sewer entry in place of a storm sewer grate. The risers 18 extend upward from the base ring 14. The screen 26 is wrapped around the support structure to allow surface water runoff to flow, but substantially prevent debris or other solid matter from entering the interior of the grate filter and subsequently the storm sewer. A cover or lid for the filtering device can be obtained in case the amount of debris retained on the sides cause the water to overtop the device. The lid may also serve to limit or prevent the unwanted placement of trash in the drainage grate filter 10 by people. FIG. 1B illustrates the drainage grate filter 10 having a screened top 33, wherein the screen 26 of the screened top 33 is located under lifting bar 30, discussed in more detail below. Of course, as those skilled in the art will appreciate, alternate configurations exist for providing a screened, covered or access limited top portion to the drainage grate filter, and such alternative are also encompassed by the scope of the present invention.

As used herein the term screen 26 refers to any media that can be wrapped or placed around the interior or exterior of the frame 15 that allows liquids to pass through it but limits passage of solid matter. By way of example and not limitation, the screen 26 may be made of any combination of a metal mesh, expanded metal, or perforated metal. Further, the screen 26 may utilize a plastic or geosynthetic material, such as a geotextile material used either alone or in conjunction with a screen 26 comprising a material made of metal. As used herein, a geotextile includes woven or non-woven fabrics including materials made of natural and/or man-made products. By way of further example, the screen 26 may include or may be fitted with a geotech fabric bag or other geosynthetic material that is slipped downward over the part or all of the drainage grate filter 10 to further reduce the openings and limit passage of materials.

By way of example and not limitation the risers 18 shown in FIG. 1A are substantially vertical. However, non-vertical risers are within the scope of the invention. As can be appreciated, such non-vertical risers may be used in connection with rings of different diameters.

Referring now to FIGS. 2-5, the top portion of the drainage grate filter 10 is shown, including portions of the frame 15. As can be seen, the frame 15 includes the base ring 14 and the top ring 32 interconnected by a plurality of risers 18. Optionally, one or more intermediate rings 22 are disposed between the base ring 14 and the top ring 32. In accordance with embodiments of the present invention, and as best seen in FIG. 5, the lower end 36 of each riser 18 is joined to the upper face 38 of the base ring 14. Similarly, the upper end 40 of each riser 18 is joined to the lower face 42 of the top ring 32. Alternatively, the ends of risers 18 may be joined to the exterior radial surface of the top ring 32 and base ring 14, or the interior radial surface of the top ring 32 and base ring 14.

As noted, one or more intermediate rings 22 may be joined to the risers 18 between the top ring 32 and base ring 14. The top ring 32, base ring 14, and the intermediate rings 22 are all centered on a common vertical axis. In accordance with embodiments of the present invention, the diameter of the intermediate rings 22 may be less than the diameter of the base ring 14 and the top ring 32. Accordingly, the exterior radial surface 44 of the intermediate rings 22 may be joined to the inside lateral surface 46 of the risers 18 that face the vertical axis. In this embodiment, the intermediate rings 22 are advantageously disposed in a position to support the screen 26 against pressures exerted by external debris and fluid flow. In accordance with another embodiment of the present invention, the diameter of the intermediate rings 22 may be greater than the diameter of the base ring 14 and top ring 32. Accordingly, the interior radial surface of the intermediate rings 22 may be joined to the surface of the risers 18 that face away from the vertical axis. In accordance with still other embodiments of the present invention, the diameter of the intermediate rings 22 may be the same as the diameter of the base ring 14 and top ring 32. Accordingly, the risers 18 may be divided into segments wherein each segment interconnects only two rings.

FIG. 4 shows the drainage grate filter 10 viewed from above the drainage grate filter 10 and looking down into the interior. For clarity, the upper portion or top of the drainage grate filter is not shown in FIG. 4. In accordance with an embodiment of the present invention, the base ring 14 of the drainage grate filter 10 may include one or more substantially horizontal members 34 crossing the base ring 14 and joined to the interior radial surface 48 of the base ring 14. The horizontal members 34 form a secondary safety grating and also act as a filter grate serving as a backup to the screen 26. In particular, the horizontal members 34 prevent unauthorized or accidental access to the storm water sewer. Furthermore, in the event that the surrounding water level rises above the height of the top ring 32, debris may flow over the top ring 32 and into the interior of the drainage grate filter 10, and should this occur, the horizontal bars 34 prevent larger pieces of debris or trash from entering the sewer.

The drainage grate filter 10 may optionally be equipped with a lifting bar 30 to aid the placement and removal of the drainage grate filter 10. In accordance with embodiments of the present invention, the lifting bar 30 may be a curved bar that is attached to opposite ends of the top ring 32. Alternatively, and by way of example and not limitation, the lifting bar 30 may be substituted with, or otherwise used with, a hook, eye bolt, and/or cable, chain or strap attached to any part of the drainage grate filter 10 to assist in the placement and removal of the drainage grate filter 10. Referring again to FIG. 1B, embodiments of the present invention may also include a screened top 33, or alternatively, a cover, lid or a series of bars or cage located at or near the top ring 32 to prevent access to the interior of the drainage grate filter 10, and to limit or prevent the placement of trash within the drainage grate filter 10. For the configuration shown in FIG. 1B, the lifting bar 30 is situated above the screen 26 of the screened top 33 to allow the drainage grate filter 10 to be lifted without damaging the screen 26.

In accordance with embodiments of the present invention, the frame 15 of grate filter 10 may be made of a weldable metal. By way of example and not limitation, weldable metals include steel and aluminum alloys. In accordance with embodiments of the present invention, the risers 18, rings 14, 22, 32, lifting bar 30, and horizontal members 34 are solid steel bars or rods preferably having sizes of between ¼ inch to 1½ inch diameter, and more preferably of between about ½ inch to 1¼ inch diameter, and more preferably yet, of between about ¾ inch to 1 inch in diameter. Furthermore, the weldable components of the drainage grate filter 10 may be joined together via welded connections. Alternatively, the frame 15 of drainage grate filter 10 may be constructed, at least in part, of a non-weldable material, such as cast iron and concrete. Further, the components of the grate filter 10 may be joined together via non-welded connections. By way of example and not limitation, such non-welded connections include press-fit, soldered, bolted, screwed, and glued connections.

The components of the drainage gate filter 10, may be of any cross-section. By way of example and not limitation, such cross-sections may include that of a circle, square, and rectangle.

In accordance with an alternative embodiment of the invention, the filter 10 is adapted to fit a rectangular shaped storm sewer opening. In particular, the base ring 14, top ring 32, and intermediate rings 22 have a rectangular shape. Furthermore, embodiments of the present invention may not include a separate component comprising the screen 26. In particular, the risers 18 may be spaced closely enough to act as the filtering mechanism. Alternatively or in addition, the drainage grate filter 10 may include a greater number of intermediate rings 22 that are spaced closely enough to act as the filtering mechanism.

Embodiments of the present invention comprise sizes suitable for replacing existing storm sewer grates, such as 2-foot diameter circular grates; however, as those skilled in the art will appreciate, other sizes can also be used. In addition, the drainage grate filter may vary in height, with typical heights of between 2 to 5 feet, and more preferably, with heights between about 2.5 to 4.5 feet, and more preferably yet, with heights between about 3.0 to 4.0 feet. In one preferred embodiment, the drainage grate filter 10 comprises sixteen (16) risers 18 having a height of about 4 feet, wherein the risers 18 are spaced apart around a 2-foot diameter circular base ring 14. The drainage grate filter 10 preferably includes at least one intermediate ring 22, or alternatively, a plurality of intermediate rings 22. By way of example and not limitation, the drainage grate filter 10 may include two intermediate rings 22, where a first intermediate ring 22 is located about 1 foot 4 inches above the base ring 14, and a second intermediate ring 22 is located about 2 feet 8 inches above the base ring 14, and wherein the top ring 32 is located about 4 feet above the base ring 14. Alternatively, the drainage grate filter 10 may comprise a plurality of intermediate rings 22, wherein the intermediate rings are not equally spaced between the base ring 14 and top ring 32.

FIG. 6 illustrates a side elevation view of the drainage grate filter 10 with portions of the screen 26 omitted for clarity to show the structure of the drainage grate filter 10. As best seen in FIG. 6, such configurations of intermediate rings 22 may be preferentially situated lower in elevation, that is, nearer the base ring 14, wherein the concentrated number of intermediate rings 22 near the base ring 14 advantageously provides lateral support for the lower portions of the risers 18 that experience higher lateral loading because of increased sediment thicknesses and/or storm water hydraulic pressures that are applied to the lower portions of the risers 18.

Referring now to FIG. 7, and in accordance with embodiments of the present invention, a wrap, covering or filter bag 52 may be used to cover the drainage grate filter 10′, wherein the drainage grate filter 10′ does not include a separate layer of screen 26 around the frame 15. That is, the filter bag 52 alone serves as the screen 26. The filter bag 52 provides a disposable structure for limiting infiltration into the frame 15 of the drainage grate filter 10′. The filter bag 52 is preferably a geosynthetic type material, such as a woven or non-woven geotextile. The filter bag 52 preferably includes a drawstring 56 that can be used to tighten the filter bag 52 around the base or other portion of the drainage grate filter 10′. Alternatively, other means for releasably securing the filter bag 52 to the frame 15 may be used, such as fasteners, elastic cords, eyelets and hooks, etc. In use, the filter bag 52 is slipped over the frame 15 to cover the frame 15.

Although the filter bag 52 is shown in FIG. 7 with frame 15 that is not surrounded by a screen 26, in an alternative embodiment, a filter bag 52 may be used with a drainage grate filter 10 that has screen 26, such as the configuration shown in FIG. 6. Such combination of first and second layers of filter material can be advantageously used to limit infiltration of finer particles into the storm sewer. Such combination of dual filter layers may be appropriate for installation at sites having storm water runoff that is carrying a relatively heavy load of sediment. Of course, if the sediment-rich runoff is temporary, once the sediment load is reduced, such as after adjacent properties are covered with sod, use of the filter bag 52 may be ended. Thus, use of a filter bag 52 may be substantially continuous or may be only temporary.

Embodiments of the present invention are particularly suited for use in parking lots and/or industrial locations where debris (including non-organic materials and/or organic matter, such as branches), trash and/or sediment needs to be prevented from entering the storm sewer. For example, many shopping mall parking areas and parking lots at gathering areas for large public events (e.g., concerts, sporting events, carnivals, etc.) often accumulate trash and other debris. Use of the drainage grate filters at storm sewer openings at these locations can prevent the trash and/or debris from entering the storm sewer during or after the storm event, while also subsequently facilitating relatively easy collection of such retained trash and/or debris above grade because it collects adjacent to the drainage grate filter.

The present invention, in various embodiments, includes components, methods, processes, systems and/or apparatus substantially as depicted and described herein, including various embodiments, subcombinations, and subsets thereof. Those of skill in the art will understand how to make and use the present invention after understanding the present disclosure. The present invention, in various embodiments, includes providing devices and processes in the absence of items not depicted and/or described herein or in various embodiments hereof, including in the absence of such items as may have been used in previous devices or processes, e.g., for improving performance, achieving ease and\or reducing cost of implementation.

It is to be noted that the term “a” or “an” entity refers to one or more of that entity. As such, the terms “a” (or “an”), “one or more” and “at least one” can be used interchangeably herein. It is also to be noted that the terms “comprising”, “including”, and “having” can be used interchangeably.

The foregoing discussion of the invention has been presented for purposes of illustration and description. The foregoing is not intended to limit the invention to the form or forms disclosed herein. In the foregoing Detailed Description for example, various features of the invention are grouped together in one or more embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the following claims are hereby incorporated into this Detailed Description, with each claim standing on its own as a separate preferred embodiment of the invention.

Moreover, though the description of the invention has included description of one or more embodiments and certain variations and modifications, other variations and modifications are within the scope of the invention, e.g., as may be within the skill and knowledge of those in the art, after understanding the present disclosure. It is intended to obtain rights which include alternative embodiments to the extent permitted, including alternate, interchangeable and/or equivalent structures, functions, ranges or steps to those claimed, whether or not such alternate, interchangeable and/or equivalent structures, functions, ranges or steps are disclosed herein, and without intending to publicly dedicate any patentable subject matter. We claim all modifications and variation coming within the spirit and scope of the following claims. 

1. A storm sewer drainage grate filter apparatus for placement on a storm drain opening, the storm drain opening located at or near a ground or pavement elevation, the apparatus comprising: a frame comprising a base ring and a top ring interconnected by a plurality of risers, wherein the base ring is adapted to engage the storm drain opening; and a passage limiting structure supported by the frame; wherein the storm sewer drainage filter is configured to be installed to extend upwards from the storm drain opening and above the ground or pavement elevation.
 2. The apparatus of claim 1, wherein the passage limiting structure comprises perforations sized to pass water and finely sized objects, but not coarsely sized objects.
 3. The apparatus of claim 1, wherein the passage limiting structure is a screen and wherein the screen surrounds substantially an exterior of the frame.
 4. The apparatus of claim 3, wherein the screen comprises at least one of a metal, plastic, and geotextile.
 5. The apparatus of claim 3, wherein the screen includes a material slipped over at least a portion of the frame to filter materials.
 6. The apparatus of claim 1, further comprising a lifting bar connected to the top ring.
 7. The apparatus of claim 1, wherein the base ring comprises a plurality of horizontal members crossing the interior of the base ring.
 8. The apparatus of claim 1, wherein an end of each riser is connected to an upper surface of the base ring.
 9. The apparatus of claim 1, wherein an end of each riser is connected to a lower surface of the top ring.
 10. The apparatus of claim 1, wherein the frame further comprises one or more intermediate rings.
 11. The apparatus of claim 10, wherein the one or more intermediate rings have a smaller diameter than the base and top rings.
 12. The apparatus of claim 11, wherein an inside lateral surface of the risers are connected to an exterior radial surface of the one or more intermediate rings.
 13. The apparatus of claim 1, wherein the frame further comprises a plurality of intermediate rings that are asymmetrically spaced along a height of the risers.
 14. The apparatus of claim 13, wherein a greater number of intermediate rings are closer to the base ring than the top ring.
 15. The apparatus of claim 1, wherein the risers extend vertically.
 16. A storm sewer drainage grate filter apparatus for placement on a storm drain opening, the storm drain opening located at or near a ground or pavement elevation, the apparatus comprising: a base ring having a first diameter and being adapted to engage the storm drain opening; a top ring having the first diameter; at least one intermediate ring disposed between the base ring and the top ring, the intermediate ring having a second diameter, the second diameter being less than the first diameter; a plurality of risers that interconnect the base ring, the top ring, and the intermediate ring such that each ring is centered on a common vertical axis, wherein a lower end of each riser is connected to an upper face of the base ring, and an upper end of each riser is connected to a lower face of the top ring, and wherein an outer radial surface of the intermediate ring is connected to an inside lateral surface of the risers; and a screen connected to an outside lateral surface of the risers opposite the intermediate rings; wherein the storm sewer drainage filter is configured to be installed to extend upwards from the storm drain opening and above the ground or pavement elevation.
 17. The apparatus of claim 16, further comprising a lifting bar connected to the top ring.
 18. The apparatus of claim 16, wherein the screen comprises at least one of a metal, plastic, and geotextile.
 19. The apparatus of claim 16, further comprising a plurality of intermediate rings that are asymmetrically spaced along a height of the risers.
 20. The apparatus of claim 19, wherein a greater number of intermediate rings are closer to the base ring than the top ring.
 21. A method for fitting a storm sewer grate filter apparatus to a storm sewer opening and filtering solid materials, the method comprising: providing an above grade drainage grate filter having a frame and screen supported by the frame, wherein the drainage grate filter is adapted to engage the storm sewer opening; allowing debris transported by storm water flow to accumulate around the exterior of the drainage grate filter; and clearing the debris from the exterior of the drainage grate filter.
 22. The method of claim 21, wherein the step of installing the storm sewer drainage grate filter includes lifting the drainage grate filter with a lifting bar.
 23. The method of claim 21, wherein the screen comprises metal.
 24. The method of claim 21, wherein the frame comprises: a base ring having a first diameter and being adapted to engage the storm drain opening; a top ring having the first diameter; at least one intermediate ring disposed between the base ring and the top ring, the intermediate ring having a second diameter, the second diameter being less than the first diameter; and a plurality of risers that interconnect the base ring, the top ring, and the intermediate ring such that each ring is centered on a common vertical axis, wherein a lower end of each riser is connected to an upper face of the base ring, and an upper end of each riser is connected to a lower face of the top ring, and wherein an outer radial surface of the intermediate ring is connected to an inside lateral surface of the riser.
 25. The method of claim 24, wherein the screen is connected to an outside lateral surface of the risers opposite the intermediate rings.
 26. The method of claim 21, wherein the screen comprises a filter bag. 